change key scheme

Author: MarinPostma

libsql-wal/src/storage/mod.rs

@@ -18,7 +18,7 @@ use crate::io::{FileExt, Io, StdIO};
 use crate::segment::compacted::CompactedSegment;
 use crate::segment::{sealed::SealedSegment, Segment};
 
-use self::backend::SegmentMeta;
+use self::backend::{FindSegmentReq, SegmentMeta};
 pub use self::error::Error;
 
 pub mod async_storage;
@@ -142,10 +142,10 @@ impl FromStr for SegmentKey {
     type Err = ();
 
     fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
-        let (rev_start_fno, s) = s.split_at(20);
-        let start_frame_no = u64::MAX - rev_start_fno.parse::<u64>().map_err(|_| ())?;
-        let (rev_end_fno, timestamp) = s[1..].split_at(20);
+        let (rev_end_fno, s) = s.split_at(20);
         let end_frame_no = u64::MAX - rev_end_fno.parse::<u64>().map_err(|_| ())?;
+        let (start_fno, timestamp) = s[1..].split_at(20);
+        let start_frame_no = start_fno.parse::<u64>().map_err(|_| ())?;
         let timestamp = timestamp[1..].parse().map_err(|_| ())?;
         Ok(Self {
             start_frame_no,
@@ -160,8 +160,8 @@ impl fmt::Display for SegmentKey {
         write!(
             f,
             "{:020}-{:020}-{:020}",
-            u64::MAX - self.start_frame_no,
             u64::MAX - self.end_frame_no,
+            self.start_frame_no,
             self.timestamp,
         )
     }